Volume 82, Issue 1

The IUPAC-sponsored 13th International Biotechnology Symposium (IBS) and Exhibition was held successfully from 12 to 17 October 2008 in Dalian, China, with about 2500 participants, including 50 % international delegates from about 80 countries. More details of the conference are available in Chemistry International 31 (3), 28-29 (2009). The theme of the conference was "Biotechnology for the sustainability of human society", through which all key biotechnology topics closely related to the better living of human beings were discussed. Examples included biopharmaceuticals and advanced diagnostic and therapeutic technologies, green biotechnology for the improvement of agricultural production yield and efficiency, industrial biotechnology for the production of biofuels and bio-based chemicals from renewable biomass resources as alternatives to fossil-based feedstocks, bioremediation of pollutants and contaminants to save the continuously deteriorating eco-environment, and biosafety and biosecurity associated with the progress of advanced biotechnology. With the sponsorships of international and domestic academic publishers, several special issues have been published for the conference, reporting or reviewing the frontiers of modern biotechnology with specific focus. It has been recognized that chemistry is the fundamental discipline to drive the progress of biotechnology R&D since its inception. This importance was highlighted by over half a century history of the IBS series dating back to as early as 1960 when the first IBS was initiated under the auspices of IUPAC in Rome, Italy, and continuously increased numbers of participants trained with chemistry backgrounds, which gives us, as the conference organizers, the pleasure of publishing this special issue in Pure and Applied Chemistry with a theme: "Building the bridge between chemistry and biotechnology". Invitations were issued to 42 Symposium presenters whose contributions were deemed to be directly relevant to the chosen theme, and resulted in this collection comprising 29 papers devoted to aspects of research progress in the interdisciplinary area of chemistry and biotechnology. Although the publication comes later than expected, we believe that its objective to highlight the critical role of chemistry in the development of biotechnology is never out of date. As the guest editors of this special issue, we are very pleased to share this publication with colleagues around the world, and we are also grateful to IUPAC, the authors, and the referees for all of their contributions toward this record of an important interdisciplinary feature of the IBS program. F. W. Bai, W. Zhang, and J.-J. Zhong Conference Editors

Flavonoids and terpenoids are promising candidates for use as functional foods and novel therapeutics due to their prominent biological activities. However, the use of several bioactive plant compounds is limited by low stability and solubility problems. This review underlines the feasibility of enzymatic synthesis of novel bioactive analogs of selected flavonoids (silybin, rutin) and terpenoids (perillyl alcohol, POH) in nonconventional reaction systems. The effect of various parameters on the enzymatic acylation and/or glucosylation of these phytochemicals was studied. Also, the role of the structure of the novel molecules in relation to their biological function was investigated in various cancer cell lines.

The number of marine natural products (MNPs) that have been applied to biotechnological industry is very limited, although nearly 20 000 new compounds were discovered from marine organisms since the birth of MNPs in the early 1970s. However, it is apparent that they have a significant potential as pharmaceuticals, cosmetics, nutraceuticals, research tools, and others. This article focuses on selective antitumor metabolites isolated from marine sponges and tunicates and their modes of action, as well as promising candidates for nontoxic antifoulants discovered from marine organisms.

An overview of the state of the art in phytofiltration of nutrients and heavy metals (HMs) from wastewaters using tropical and subtropical plants in constructed wetlands (CWs) and lagoons is presented. Various mechanisms to remove these pollutants are discussed, in regard to three different types of systems: surface flow constructed wetlands (SFCWs), subsurface flow constructed wetlands (SSFCWs), and lagoons with floating plants. Only recent reports at laboratory, pilot and full scale, especially in tropical regions, are discussed. Most of the experiences around the world have shown that these systems are efficient and high removal percentages have been reported for both, nutrients and metals. However, there are still several unsolved or partially understood issues. Long-term studies at the mesocosms or large scale, in order to gain a full insight of the various mechanisms occurring in each system, are required. The understanding of the fate or compartmentalization of the pollutants in these complex artificial ecosystems, especially in the case of HMs, will permit us to establish the frequency of harvesting and the advantages of the use of specific species. The huge bio-diversity that is commonly found in tropical and subtropical regions represents a challenge for finding new species with outstanding characteristics for tolerance to toxic and recalcitrant pollutants or to extreme environmental conditions, such as high temperature or salinity.

Immobilized metal-ion affinity (IMA) adsorption is a collective term that is used to include all kinds of adsorptions where the metal ion serves as the characteristic and most essential part of adsorption center. Of all the IMA techniques, immobilized metal-affinity chromatography (IMAC) has been gaining popularity as the choice of purification technique for proteins. IMAC represents a separation technique that is primarily useful for proteins with natural surface exposed-histidine residues and for recombinant proteins with engineered histidine tag. This review also gives insight into other nonchromatographic applications of IMA adsorption such as immobilized metal-ion affinity gel electrophoresis (IMAGE), immobilized metal-ion affinity capillary electrophoresis (IMACE), and immobilized metal-ion affinity partitioning (IMAP).

In an age of burgeoning information on genomes and proteomes, determining the specific functions of a gene of interest is still a challenging task, especially genes whose functions cannot be predicted from their sequence information alone. To solve this problem, we have developed an integrative approach for discovering novel transcriptional regulators (TRs) playing critical roles in antibiotic production and decoding their regulatory networks in Streptomyces species which contain many regulatory genes for synthesis of secondary metabolites and cell differentiation to spores. The DNA affinity capture assay (DACA) coupled with clustering of DNA chip data was used to find new TRs controlling antibiotic biosynthetic gene clusters. Functions of these newly identified TRs were characterized using 96-well-based minimal media screening (antibiotic production mapping, APM), pH indicator method, comparative two-dimensional gel electrophoresis (2D-gel), reverse-transcription polymerase chain reaction (RT-PCR), electrophoretic mobility shift assay (EMSA), and scanning electron microscopy (SEM). Using these techniques, we were able to reconstruct a regulatory network describing how these new TRs collectively regulate antibiotic production. This proposed approach providing additional key regulators and their interactions to an existing incomplete regulatory network can also be applied in studying regulators in other bacteria of interest.

The surveillance of foodborne pathogens in food industries has shown the urgent need for rapid and dependable methods to detect and characterize the organisms in food and environments of clinical and epidemiologic importance. Recent studies on rapid methods in microbiology have been focused on biochemical characterization, immunoassays, and molecular methods. Many molecular methods have been developed and applied to the detection and characterization of foodborne pathogens in laboratories and food industries. They can be mainly divided into DNA banding pattern-based tests and DNA sequence-based tests. The former includes nucleic acid hybridization, polymerase chain reaction (PCR), amplified restriction length polymorphism, and randomly amplified polymorphic DNA, etc. Most of these methods in commercial applications are based on PCR or hybridization techniques. The principle, characteristics, and application of molecular methods for the detection and characterization of foodborne pathogens were reviewed in this article.

Gold nanoparticles (AuNPs) have been extensively employed in biological studies for several decades. More recently, progress has well demonstrated that DNA-conjugated AuNPs are highly promising nanoprobes for the sensitive detection of various biomolecules, based on the unique optical and electronic properties of AuNPs. In this short review, we focus on the use of AuNP-based nanoprobes for biological detection of nucleic acids, proteins, and other biologically relevant small-molecule targets, mainly based on the recent progress in our laboratory.

A single mature adhesive disc of Parthenocissus tricuspidata has an average mass of only about 0.0005 g, an average attached area of about 1.22 mm 2 , and an adhesive force of about 13.7 N. On average, the disc can support a combined weight of stem, leaf, branchlet, and tendril which is 260 times greater than its own weight during the growth, and can sustain a maximum pulling force which is 2 800 000 times higher than that produced by its own weight. Experimental studies reveal that the adhesive disc of P. tricuspidata has super-adhesive properties. Microscopic experiments show some new microstructures, and we propose a new hypothesis and model to elucidate the mechanism of adhesion.

Biosurfactants are surface-active compounds synthesized by a wide variety of micro-organisms. They are molecules that have both hydrophobic and -philic domains and are capable of lowering the surface tension and the interfacial tension of the growth medium. Biosurfactants possess different chemical structures—lipopeptides, glycolipids, neutral lipids, and fatty acids. They are nontoxic biomolecules that are biodegradable. Biosurfactants also exhibit strong emulsification of hydrophobic compounds and form stable emulsions. Polycyclic aromatic hydrocarbons (PAHs), crude oil sludge, and pesticides can be toxic, mutagenic, and carcinogenic compounds that pollute the environment. They are released into the environment as a result of oil spillage and by-products of coal treatment processes. The low water solubility of these compounds limits their availability to microorganisms, which is a potential problem for bioremediation of contaminated sites. Microbially produced surfactants enhance the bioavailability of these hydrophobic compounds for bioremediation. Therefore, biosurfactant-enhanced solubility of pollutants has potential bioremediation applications.

Although "Prelog’s rule" and "two hydrophobic binding pockets" model have been used to predict and explain the stereoselectivity of enzymatic ketone reduction, the molecular basis of stereorecognition by carbonyl reductases has not been well understood. The stereoselectivity is not only determined by the structures of enzymes and substrates, but also affected by the reaction conditions such as temperature and reaction medium. Structural analysis coupled with site-directed mutagenesis of stereocomplementary carbonyl reductases readily reveals the key elements of controlling stereoselectivity in these enzymes. In our studies, enzyme-substrate docking and molecular modeling have been engaged to understand the enantioselectivity diversity of the carbonyl reductase from Sporobolomyces salmonicolor (SSCR), and to guide site-saturation mutagenesis for altering the enantioselectivity of this enzyme. These studies provide valuable information for our understanding of how the residues involved in substrate binding affect the orientation of bound substrate, and thus control the reaction stereoselectivity. The in silico docking-guided semi-rational approach should be a useful methodology for discovery of new carbonyl reductases.

Genetically modified organisms (GMOs) have been developed and commercialized in many countries for the past decade. The regulations on these GMOs in Korea have been established through the labeling and safety evaluation systems for management of genetically modified (GM) foods under the Food Sanitation Act enacted by the Korea Food and Drug Administration (KFDA). To manage these regulations effectively, several methods for GMO detection, including polymerase chain reaction (PCR) methods and immunoassay, are applied. For detection of GMOs at the level of DNA, primers from the promoter, terminator, other marker genes, and expressed proteins used in a wide range of GMOs were designed for single, multiplex, real-time PCR, and microarray applications. In Korea, multiplex PCR methods specific to GM soybean, maize, canola, and cotton were designed. The limit of detection (LOD) value was determined to be 1 % of GM mixtures, which is a significant value for the PCR method used for the labeling threshold in Korea. A DNA microarray chip was also developed for the detection of 24 GMOs, including GM soybeans, 13 GM maizes, 3 GM canolas, 5 GM cottons, and 1 GM rice. This DNA chip was proven to successfully detect GMOs from raw and processed foods. In the near future, more powerful screening and detection methods are needed for handling many kinds of GMOs and unauthorized GMOs.

The Japanese government introduced a labeling system for genetically modified (GM) foods. To ensure the authenticity of the labeling system, we have developed and validated detection methods for newly approved GM events. One was the development of quantitative analytical methods utilizing plasmid DNAs as calibrators, which enabled us to obtain an unlimited supply of calibrators of consistent quality and also to obtain a stable standard curve to quantify GM organisms (GMOs) in samples. The significance of quality control has been recognized among relevant stakeholders, and in response we launched a project to distribute certified reference materials (CRMs) to the users of our methods for the purpose of internal quality control. In addition to these activities, we have developed time- and cost-effective detection methods, such as a new screening method to simultaneously detect the sequence of Cauliflower mosaic virus 35S promoter (p35S) and the construct-specific sequence of GA21 event utilizing multiplex real-time polymerase chain reaction (PCR). We also developed a qualitative nonaplex PCR detection method, which allows the simultaneous detection of eight events of GM maize lines. Because the influx of any unapproved and unknown GMOs into the Japanese market is not permitted, we continue to explore this issue.

As a comparative study, the extracytoplasmic domain of human CD83 (hCD83ext) was expressed as a glutathione- S -transferase (GST) fusion in two Escherichia coli B strains, i.e., BL21 and Origami B, respectively, with a reductive and oxidative cytoplasm. The final therapeutic products of hCD83ext produced by the two expression hosts exhibited significant differences in protein conformation and molecular property, which presumably resulted from different disulfide patterns. The study highlights the importance of developing proper host/vector systems and biomanufacturing conditions for the production of recombinant therapeutic proteins with a consistent product quality.

A former open-cast pit was used as the disposal site for wastewater from lignite low-temperature coking processes. The formed lake with a strong stratification had a final volume of 2 × 10 6 m 3 . Its water was highly toxic and of dark brownish color (transparency about 3 cm). Traditional remediation methods were too expensive, and it was therefore necessary to develop a new, ecologically and economically acceptable remediation strategy. This strategy is based on a first precipitation step of the dark-brown-colored macromolecules as iron-humate flocs at pH 4.0. These macromolecules are similar to fulvic/humic acid and are formed abiotically by autoxidation of polyphenolic compounds. Thus, the dissolved organic matter (DOM, about 280 mg/l) was decreased by about 50 % and transparency improved. After a neutralization step with 2200 m 3 of 20 % calcium carbonate suspension and a subsequent "fertilization" with 0.75 % phosphoric acid (3 × 0.8 m 3 ) "enhanced natural attenuation" was initiated. Due to higher transparency, intense growth of algae ("blooming") and bacteria started in the upper zone of the lake. In winter, algae sedimented and one year after the precipitation step, the water of the surface zone was almost clear (transparency 1 m, after 10 years over 3 m) and odorless.

The hexactinellid sponge Monorhaphis chuni possesses with its giant basal spicules the largest biosilica structure on Earth. The approximately 8.5-mm-thick spicules are composed of up to 800 lamellae. By application of high-resolution electron microscopy (HR-SEM), it is shown that within the siliceous lamellae a proteinaceous scaffold exists which is composed of one protein of a size of 27 kDa. Analyses with Fourier transform infrared (FT-IR) emission and energy-dispersive X-ray (EDX) spectroscopy support this localization of the protein. No evidence for the presence of protein on the surfaces of the lamellae could be obtained. Heating the giant basal spicule to 600 °C destroys and eliminates the protein scaffold. At a temperature of 1600 °C, the lamellae fuse to solid glass via a nonstructured, foamed-up molten transition state. Elevation of the temperature to 2700 °C results in the formation of silica drops ( Euplectella aspergillum ). After the elimination of the protein scaffold from the silica lamellae, the spicules lose their mechanical characteristics of the original hydrated silica/protein composite to be flexible and simultaneously stiff and tough. The data presented here are expected to contribute to technologies suited to fabricate novel organic/inorganic (silica) hybrid fibers.

The high-affinity cohesin–dockerin interaction dictates the suprastructural assembly of the multienzyme cellulosome complex. The interaction between these two complementary families of protein modules was found to be species-specific and type-dependent. The structure of the type II cohesin module possesses additional intrinsic secondary structural elements absent in the type I cohesin, i.e., an α-helix and two singular "β-flaps". The role of these extra secondary structures in dockerin recognition was studied in this work using gene swapping, in which corresponding homologous stretches of types I and II cohesins were interchanged. The specificity of binding of the resultant chimaeric cohesins was determined by enzyme-linked affinity assay. Several chimaeric cohesins retained dockerin recognition properties. Hence, these cohesins may undergo manipulations (insertion/deletion of peptide segments) without altering their affinity toward their counterpart dockerin, although type-dependent binding specificity cannot be converted by swapping of the additional secondary structural elements between the two cohesin types. The results further emphasize the strong affinity and plasticity between the cohesin and dockerin pair and are consistent with the known findings on specificity of the types I and II interactions. These studies provide insight into the structural and functional resilience of the cohesins and thus have direct bearing on their potential use in biotechnological applications.

Single-chain-Fv (scFv) display M13 phage library has been regarded as a powerful tool for screening specific antibodies via binding with target proteins. Generally, the library quality is evaluated through detecting gene fragments by molecular biology methods, which is not only time- and labor-consuming, but also impossible to obtain quantitative information about the binding capacity of the phage library. In our recent study, a new method to calculate the average scFv number displayed on the M13 phage surface was proposed by capillary electrophoresis with laser-induced fluorescence (CE-LIF) detection. By this method, enhanced green fluorescent protein (EGFP) and scFv phage clones that could specifically bind with EGFP were mixed with different ratios, followed by analysis by CE-LIF. With the dilution of EGFP by phage solution, the peak areas of scFv phage clones and free EGFP were decreased continuously, while that of the EGFP-M13 phage complex was found to decrease initially, then trend to be stable, and finally decrease further. When the volume ratio of the M13 phage to EGFP reached 660:1, corresponding to the molecule number ratio as 1:2.6, no more EGFP was found to bind with the M13 phage, which demonstrated that, by average, 2.6 scFv fragments that could bind with EGFP were displayed on the M13 phage surface. All these experimental results demonstrated that, by such a method, the quantitative evaluation of the phage library could be achieved with high throughput and accuracy.

Camptothecin is one of the clinically used anticancer compounds derived from plants. We have established a hairy root culture Ophiorrhiza pumila , which efficiently produces camptothecin. The strictosidine synthase cDNA was obtained from O. pumila , and its properties were characterized using recombinant protein expressed in Escherichia coli . The mechanisms of camptothecin transport and self-resistance of producing plant cells have also been investigated. These studies offer a basis for pathway engineering of camptothecin in the future.

Chlorogenic acid is a polyphenol compound, derived from several fruit and plants. The aim of this study was to assess the in vitro antifungal activity of chlorogenic acid and its mode of action. The results indicate that chlorogenic acid exhibits antifungal activities against certain pathogenic fungi in an energy-independent manner, without any hemolytic effect on human erythrocytes. To elucidate the antifungal mode of action of chlorogenic acid, flow cytometry analysis by using DiBAC 4 (3) and changes in membrane dynamics using 1,6-diphenyl-1,3,5-hexatriene (DPH) were performed with Candida albicans . The results suggest that chlorogenic acid may exert antifungal activity by disrupting the structure of the cell membrane. It is demonstrated that chlorogenic acid is a valid lead compound for the development of bioactive alternatives for treatment of fungal infections.

To investigate the plant growth-promoting effect and stimulation of lignan biosynthesis, the effect of culture filtrates/live co-culture of two arbuscular mycorrhizae-like fungi, Piriformospora indica and Sebacina vermifera , on growth of Linum album cells and on production of podophyllotoxin (PT) and 6-methoxypodophyllotoxin (6-MPT) was studied. For elicitation studies, different volumes of culture filtrates (autoclaved and membrane-filtered) of P. indica/S. vermifera were added to suspension cultures of L. album . The culture filtrates of both the fungi exhibited a positive effect on product formation. For co-culture experiments, both fungi were individually co-cultivated at different concentrations with L. album in suspension cultures for different time periods. This resulted in significant enhancement of PT and 6-MPT content in the plant cells. The activity of phenylalanine ammonia lyase (PAL) was observed to be related to the lignan accumulation, indicating its role as the key enzyme of the phenylpropanoid pathway. The study resulted in total lignan (PT and 6-MPT) production of 745.6 mg/l with a very high PT productivity of 52.4 mg/(l.d).

In the present study, the 26-residue peptide sequence Ac-KWKSFLKTFKSAKKTVLHTALKAISS-amide (peptide P) was utilized as the framework to study the effects of introducing hydrophilic amino acid lysine on the nonpolar face of the helix on peptide biological activities. Lysine residue was systematically used to substitute original hydrophobic amino acid at the selected locations on the nonpolar face of peptide P. In order to compensate for the loss of hydrophobicity caused by lysine substitution, leucine was also used to replace original alanine to increase peptide overall hydrophobicity. Hemolytic activity is correlated with peptide hydrophobicity. By introducing lysine on the nonpolar face, we significantly weaken peptide hemolytic activity as well as antimicrobial activity. However, by utilizing leucine to compensate the hydrophobicity, we improve antimicrobial activity against both Gram-negative and -positive bacteria. Peptide self-association ability and hydrophobicity were also determined. This specific rational approach of peptide design could be a powerful method to optimize antimicrobial peptides with clinical potential as peptide antibiotics.

Castor bean ( Ricinus communis L.) seeds serve as raw material for the production of nonedible oil used in medicine and industry, whereas the presence of allergenic and toxic proteins in the residue left after oil extraction precludes the use of this protein-rich by-product in animal feeding. To better understand the enzymes involved in the biosynthesis and degradation of fatty acids and to identify proteins with toxic/anti-nutritional properties, extracts of developing and germinating seeds were prepared and prefractionated according to solubility properties of the proteins. An enriched plastid organelle fraction embracing mostly plastids and mitochondria was also prepared. Two-dimensional electrophoresis (2DE) reference maps of these fractions were obtained from which nearly 400 proteins were identified by matrix-assisted laser desorption ionization-time of flight-time of flight (MALDI-TOF-TOF) mass spectrometry after a search in a National Center for Biotechnology Information (NCBI) database and in an expressed sequence tag (EST) primary bank prepared from a cDNA library of developing seeds. These proteomics techniques resulted in the identification of several classes of seed reserve proteins such as 2S albumins, legumin-like and seed storage proteins, as well as other proteins of plastidial or mitochondrial functions and proteins involved in plant defense against biotic and abiotic stresses. It is expected that the collected data will facilitate the application of genetic techniques to improve the quality/profile of castor seed fatty acids, and pave the way for a rational approach to inactivate allergenic and toxic proteins, allowing the use of castor bean meal in animal feeding.

Recently, people have been paying greater attention to their health and, as a result, the need to use physiologically functional foods was found on the market. For these reasons, the market size of “foods for specified health use” (FOSHU) in Japan has grown and was approximately ¥700 billion in 2008. Many enzymes such as amylases and proteases have been used in food manufacturing because of their diversity, specificity, and mild condition in reaction. The aim of this investigation was the production of novel bioactive compounds by three kinds of transglycosylation reaction of the amylolytic enzymes, and the research and development of physiologically functional foods using these compounds. Phosphoryl oligosaccharides of calcium (POs-Ca) are a complex with Ca and phosphoryl oligosaccharides prepared from potato starch by a hydrolysis (transglycosylation to H 2 O) of amylolytic enzymes. The chewing gum included POs-Ca prevented dental caries in humans. Highly branched cyclic dextrin (HBCD) was produced from amylopectin by branching enzyme (intramolecular transglycosylation), which had a relatively narrow molecular-weight distribution compared with commercially available dextrins. The sports drink containing HBCD enhanced swimming endurance in mice and humans. α-Glycosylhesperidin (G-Hsp) was produced from starch and hesperidin, a flavonoid found abundantly in citrus fruits, by the intermolecular transglycosylation using cyclodextrin glucanotransferase. Oral administration of G-Hsp improved rheumatoid arthritis in mice and humans, and poor blood circulation in women. In this study, we looked to prove that this enzymatic modification technique was useful in creating unique and effective physiologically functional foods. These functional foods are expected to improve the health and quality of life of many people.

For efficient and profitable crop production, appropriate weed management is essential. Today, herbicides are an integral part of modern farming practice globally, as they assure the convenient method of weed control chemically. Glutathione S- transferases (GSTs, EC.2.5.1.18) are a superfamily of multifunctional enzymes that detoxify endo- and xeno-biotic compounds by conjugating glutathione (GSH) to a hydrophobic substrate. Plant GSTs have been a focus of attention because of their roles in herbicide detoxification and environmental safety. In this study, the application of herbicide called tribenuron-methyl to the cultivars of wheat ( Triticum aestivum L. cv. Izgi-2001, Triticum aestivum L. cv. Alpu-2001) and barley plants ( Hordeum vulgare L. cv. Bilgi-91, Hordeum vulgare L. cv. Kalayci-97) caused an increase in GST activities of both in roots and shoots. Total GSH and protein contents were also determined for all above-mentioned plants. As a conclusion, our results indicate that depending on the herbicide itself, treatment conditions and the origin of the plant, tribenuron-methyl had an effect on the parameters measured in this study, including the GST activities and synthesis of GSH. The maximum increase in enzyme activity was observed in herbicide-treated Triticum aestivum L. cv. Izgi-2001 roots: 192 % of control with a tribenuron-methyl concentration of 1.5 M. However, further investigations are needed to elucidate the presence of specific tribenuron-methyl GST isozymes in this plant.

Microbial community structures in sequencing batch reactors (SBRs) for azo dye wastewater treatment were analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Effects of dye concentration and salinity were investigated for the decolorization of both reactive brilliant red K-2G and KE-3B. The results showed that the microbial community exhibited high color removal efficiency with high concentration of K-2G (1100 mg/l) and moderate KE-3B (400 mg/l), respectively. Under high-salt conditions, decolorization of KE-3B was partially inhibited, while little effect was observed on decolorization of K-2G. The results of similarity analysis demonstrated that the DGGE banding patterns of microbial communities in K-2G and KE-3B decolorization systems were clustered into two independent groups. And it was suggested that the microbial diversities shifted proportionally with the decolorization rates for both dyes. The similarity index (Cs) of the bacterial communities under higher-salt conditions was more than those cultured with lower salinity. It was also found that microbial diversities turned out to be more abundant for both dyes with the increase of NaCl concentration. These results suggested that not only the stability but also the adequate dynamics and diversity of the microbial community structure are important for the stable performance of the SBRs treating hyper-salinity azo dye wastewater.

Fluorescence has advanced our understanding in various aspects of biological processes. Fluorescence in the near infrared (NIR) region avoids background autofluorescence from biological samples, leading to improved image quality. In searching for indo-cyanine green (ICG) analogs that can be attached to biomolecules, we observed that dichromic fluorescence manifested in some mono reactive-group-functionalized ICG analogs. The two emission bands are distinctively separate from each other, making it a unique feature of fluorescent probes found in biological studies. We further demonstrated that the dichromism comes from the structure and is transferable from dye to its bioconjugates. In this paper, we used resonance theory and molecular orbital theory to explain the fluorophore photochemistry in an effort to understand the general fluorescence feature of ICG analogs and provide understanding of the secondary emission band.

Plant-associated bacteria are known to improve plant growth and play a major role in the development of plants. The present study is concerned with the isolation of two auxin-producing plant growth-promoting bacteria (PGPB). On the basis of 16S rRNA sequencing, both of the strains are identified as Bacillus sp. Maximum auxin production was observed at 37 °C after 48 h of incubation. Increase in tryptophan concentration stimulated auxin production by the isolates. High-performance liquid chromatography analysis showed that the bacterial auxin exhibited similar retention time as the standard indole-3-acetic acid (IAA). Sprouts of Solanum tuberosum var. Desiree were inoculated with the isolates. Comparison of various growth parameters of inoculated plants with non-inoculated plants revealed the improvement of plant growth by bacterial inoculation. Almost 40 and 35 % increase in shoot length with P4 and S6 inoculation, respectively, was observed. Considerable improvement in root growth was observed with an increase in the number and length of roots. On the basis of the above findings, it is concluded that the plant growth-promoting Bacillus strains affect S. tuberosum beneficially, resulting in improved plant growth.

It has been well recognized that cardiovascular diseases are closely related to blood flow characteristics. Thus, how to predict them accurately enough in an efficient way has been an important research issue. This paper introduces a 1D spectral element model for the blood flow in the human arteries with varying cross-sections. The variational approach is used to formulate the 1D spectral element model. The exact wave solutions to the frequency-domain governing differential equations are used to determine the frequency-dependent shape functions. The spectral finite element model is then applied to some example arteries to investigate flow characteristics such as blood flow rate and blood pressure through the arteries.

A novel series of compounds, derived from [1,2,3]triazolo[4,5- d ]pyrimidines with a guanidyl group or amino group-terminated side chain was designed and synthesized as HIV-1 trans-activator of transcription–trans-activation responsive region (Tat–TAR) interaction inhibitors. Their ability to inhibit Tat–TAR RNA interaction was determined by a Tat-dependent HIV-1 long terminal repeat (LTR)-driven chloramphenicol acetyltransferase (CAT) assay and simian immunodeficiency virus (SIV)-induced syncytium evaluation. The binding of the compounds with TAR RNA was conducted by molecular modeling and capillary electrophoresis (CE) analysis. The results showed that all the compounds could block the Tat–TAR interaction and have antiviral activities.